In any communication system including several users sharing the transmission medium, i.e., the available communication resources, special attention must be given to the co-existence of the different signals being present within the communication system. The users of the communication system generally share the same pool of communication resources. When allocating the communication resources (for example, different channels) to the multiple users, it is realized that the signal of one user may affect (interfere with) the signal of another user. A communications system designer thus has to design a user traffic multiplexing scheme bearing this in mind, and thus design the multiplexing scheme so as to handle this undesired interference.
In communication systems in which a geographical division is used, e.g., a cellular system, there are mainly two kinds of multi-user interference present. Firstly, the interference from users within the same geographical area, called a cell; the so called intra-cell interference, and secondly the interference from users in adjacent (neighboring) cells; the so called inter-cell interference. When the cell size is small, more than one adjacent cell can interfere with any given cell. In the literature, base station or evolved Node B NB is also a term used for a cell.
eNodeB is also commonly referred to as base station (BS), base transceiver station, controller, access point (AP), access network (AN), and so forth, while a user equipment (UE) may also be commonly referred to as mobile station (MS), access terminal (AT), subscribers, subscriber stations, terminals, mobile stations, and so on.
One of the challenges for OFDM cellular networks such as LTE and/or WiMax includes mitigating inter-cell interference.